A case of methicillin-resistant Staphylococcus aureus wound infection: phylogenetic analysis to establish if nosocomial or community acquired

Active Surveillance Cultures and Procalcitonin in Combination With Clinical Data to Guide Empirical Antimicrobial Therapy in Hospitalized Medical Patients With Sepsis

Objective

The prevalence of colonization with multidrug-resistant organisms (MDRO) has increased over the last decade, reaching levels as high as 23% in certain patient populations. Active surveillance cultures (ASC) represent a valuable tool to identify patients colonized with MDRO to apply preventive measures, reduce transmission, and guide empiric antimicrobial therapy. There is a paucity of data evaluating the impact of admission ASCs to predict future infection. The aim of this study was to evaluate the concordance between ASCs results and the development of clinical infection by the same microorganism identified in the surveillance swab ("swab-related infection"), in hospitalized septic patients, and to evaluate the presence of specific risk factors associated with the development of a swab-related infection.

Methods

All adults admitted to the Diagnostic and Therapeutic Medicine Department of the University Hospital Campus Bio-Medico of Rome with a diagnosis of infection or any other medical reason with admission surveillance swabs (rectal or nasal) between January 2018 and February 2021 were included in the study. A retrospective chart review was conducted to identify patients that developed infections with concordant MDROs identified on ASC, and the risk factors for swab-related infection. Secondary outcomes were need of intensive care unit transfer, length of stay, sepsis or septic shock development, and all-cause mortality.

Results

A total of 528 patients were included in the study, of which 97 (18.3%) had a positive surveillance swab. Among patients with positive surveillance swabs, 18 (18.5%) developed an infection with the same microorganism recovered from the swab, 57 (58.8%) developed an infection with a different microorganism than that recovered from the surveillance swab, and 22 (22.7%) did not develop an infection during hospitalization. The number of colonized sites, an interventional procedure within the previous 3 months, a Systemic Inflammatory Response Syndrome (SIRS) score ≥ 2, and a quick Sequential Organ Failure Assessment (q-SOFA) score ≥ 2 were associated with a significantly higher risk of developing a swab-related infection. SIRS and q-SOFA scores ≥ 2 and procalcitonin ≥ 0.43 ng/ml help for identifying patients with a swab-related infection.

Conclusion

Patients with positive surveillance swabs were at increased risk for development of infections by the same MDRO identified in surveillance swabs (swab-related infection). This study is the first to show that the positivity of surveillance swabs, in combination with anamnestic data, PCT values, and SIRS or q-SOFA scores, serves as a valuable tool to help clinicians predict patients at higher risk for swab-related infection development and guide the administration of appropriate empiric antimicrobial therapy in septic patients.

Teicoplanin combined with conventional vancomycin therapy for the treatment of pulmonary methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis infections

BACKGROUND

Vancomycin and teicoplanin are both antibiotics that have significant antimicrobial effects on Gram-positive cocci.

AIM

To explore the value of teicoplanin combined with conventional (vancomycin only) anti-infective therapy for the treatment of methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis pulmonary infections.

METHODS

A total of 86 patients with methicillin-resistant Staphylococcus aureus or methicillin-resistant Staphylococcus epidermidis pulmonary infections, treated in our hospital between January 2018 and February 2020, were assigned to the study and control groups using a random number table method, with 43 patients in each group. The control group received conventional treatment (vancomycin), and the study group received both teicoplanin and conventional treatment. The following indicators were assessed in both groups: the time required for symptom relief, treatment effectiveness, serum levels of inflammatory factors (procalcitonin, interleukin-1β, tumor necrosis factor-α, C-reactive protein), clinical pulmonary infection scores before and after treatment, and the incidence of adverse reactions.

RESULTS

Patients in the study group were observed to have faster cough and expectoration resolution, white blood cell count normalization, body temperature normalization, and rales disappearance than patients in the control group (all P < 0.05); the total rate of effectiveness was 93.02% in the study group, higher than the 76.74% in the control group (P < 0.05). The pre-treatment serum levels of procalcitonin, interleukin-1β, tumor necrosis factor-α, and C-reactive protein as well as the clinical pulmonary infection scores were similar among the patients in both groups. However, the post-treatment serum levels of procalcitonin, interleukin-1β, tumor necrosis factor-α, and C-reactive protein as well as the clinical pulmonary infection scores were significantly lower in the study group than in the control group (P < 0.05). There was no significant difference in the incidence of adverse reactions between the groups.

CONCLUSION

Compared with conventional (vancomycin only) therapy, teicoplanin and vancomycin combination therapy for patients with pulmonary methicillin-resistant Staphylococcus aureus and methicillin-resistant Staphylococcus epidermidis infections can improve patient clinical symptoms, modulate serum inflammatory factor levels, and improve treatment efficacy, without increasing the risk of adverse reactions.

Diagnostic Accuracy and Prognostic Value of Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratios in Septic Patients outside the Intensive Care Unit

Background and Objectives: The aim of this study was to evaluate the diagnostic accuracy and prognostic value of neutrophil-to-lymphocyte (NLR) and platelet-to-lymphocyte (PLR) ratios and to compare them with other biomarkers and clinical scores of sepsis outside the intensive care unit. Materials and methods: In this retrospective study, 251 patients with sepsis and 126 patients with infection other than sepsis were enrolled. NLR and PLR were calculated as the ratio between absolute values of neutrophils, lymphocytes, and platelets by complete blood counts performed on whole blood by Sysmex XE-9000 (Dasit, Italy) following the manufacturer’s instruction. Results: The best NLR value in diagnosis of sepsis was 7.97 with sensibility, specificity, AUC, PPV, and NPV of 64.26%, 80.16%, 0.74 (p < 0.001), 86.49%, and 53.18%, respectively. The diagnostic role of NLR significantly increases when PLR, C-reactive protein (PCR), procalcitonin (PCT), and mid-regional pro-adrenomedullin (MR-proADM) values, as well as systemic inflammatory re-sponse syndrome (SIRS), sequential organ failure assessment (SOFA), and quick-sequential organ failure assessment (qSOFA) scores, were added to the model. The best value of NLR in predicting 90-day mortality was 9.05 with sensibility, specificity, AUC, PPV, and NPV of 69.57%, 61.44%, 0.66 (p < 0.0001), 28.9%, and 89.9%, respectively. Sensibility, specificity, AUC, PPV, and NPV of NLR increase if PLR, PCR, PCT, MR-proADM, SIRS, qSOFA, and SOFA scores are added to NLR. Conclusions: NLR and PLR represent a widely useful and cheap tool in diagnosis and in predict-ing 90-day mortality in patients with sepsis.

Genetic diversity of Staphylococcus aureus influences disease phenotype of systemic lupus erythematosus

OBJECTIVE

We investigated the genetic diversity, molecular epidemiology and evolutionary dynamics of Staphylococcus aureus (SA) isolated from SLE patients by means of phylogenetic analysis.

METHODS

Consecutive SLE patients (ACR 1997 criteria) were enrolled: clinical/laboratory data were collected and nasal swab for SA identification was performed. On the basis of the translation elongation factor (tuf) gene, a phylogenetic analysis was performed to investigate relationships and to assess significant clades. Selective pressure analysis was used to investigate the evolution of the SA tuf gene. The gene sequences from non-SLE individuals, downloaded from the GenBank database, were compared through phylogenetic analysis with the tuf gene from SLE patients.

RESULTS

We enrolled 118 patients [M/F 10/108; median (interquartile range (IQR)) age 45.5 (13.2) years; median (IQR) disease duration 120 (144) months]. Twenty-four patients (20.3%) were SA carriers (SA+), three of them MRSA. SA+ SLE showed significantly higher SLEDAI-2k values [SA+: median (IQR) 2 (3.75); SA-: 0 (2); P = 0.04]. The phylogenetic analysis, restricted to 21 non-MRSA SA+, revealed a statistically supported larger clade (A, n = 17) and a smaller one (B, n = 4). Patients located in clade A showed a significantly higher prevalence of joint involvement (88.2%) in comparison with clade B (50.0%, P < 0.0001) and SA- (62.7%, P < 0.0001). Haematological manifestations were significantly more frequent in clade A (64.7%) compared with B (50.0%, P = 0.004).

CONCLUSION

We suggest a possible role of SA nasal carriage status in SLE disease activity. Moreover, our findings support the hypothesis that bacterial genetic variants may be associated with specific disease features.

A Staphylococcus aureus Coinfection on a COVID-19 Pneumonia in a Breast Cancer Patient

Introduction

Coronavirus disease 19 (COVID-19), due to severe acute respiratory syndrome-coronavirus 2 (SARS-CoV2), comprises a broad spectrum of clinical presentation ranging from flu-like syndrome to organ failure. The risk of coinfections is high and responsible for a worse prognosis, mainly in the case of bacterial involvement and in the presence of particular comorbidity. We present the clinical, laboratory, radiologic characteristic along with therapeutic management of a patient with COVID-19 and Staphylococcus aureus coinfection.

Case Presentation

A 55-year-old Caucasian woman was admitted to our hospital due to a two-day history of fever and acute dyspnea with severe respiratory failure worsened after the administration of atezolizumab and nab-paclitaxel. Her medical history comprehended a triple negative, BRCA1-related, PD-L1 positive right breast cancer with multiple bone metastasis, causing bone marrow infiltration-related severe pancytopenia. Her physical examination revealed scattered wheezes, rales, and bilateral dry crackles in the middle and lower lung fields and lower limb paresis. The body mass index was 30 kg/m² and arterial blood gas evaluation revealed a stage III acute respiratory distress syndrome. Microbiological specimens revealed a Staphylococcus aureus positivity from endotracheal aspirate. The chest computed tomography (CT) scan showed the presence of large areas of parenchymal consolidation and aerial bronchogram, bilateral “ground glass” areas reaching the highest extension on the upper and middle zones. The high clinical and radiological suspicion of COVID-19 along with the negative result of nasopharyngeal specimen make necessary an endotracheal aspirate resulting positive for SARS-CoV2. Patient started an antimicrobial treatment and lopinavir-ritonavir plus hydroxychloroquine but, unfortunately, died five days after hospital admission.

Conclusion

The high risk of mortality of our patient was due to viral-bacterial coinfection, advanced cancer status with active immunotherapy. This case highlights the need for a prompt clinical, laboratory, and radiological evaluation to allow a correct diagnosis and start a specific therapy.

Celery (Apium graveolens) as a potential antibacterial agent and its effect on cytokeratin-17 and other healing promoters in skin wounds infected with methicillin-resistant Staphylococcus aureus

Background and Aim:

Antimicrobial resistance is a global problem caused by extensive utilization of antibiotics that promote gene resistant among bacteria, including Staphylococcus aureus. This study aimed to analyze the potential effects of celery (Apium graveolens) extract as an antioxidant and antimicrobial agent against methicillin-resistant S. aureus (MRSA), in vitro and in vivo.

Materials and Methods:

Celery was extracted and tested against a MRSA isolate in vitro. The minimum inhibitory concentration (MIC) against MRSA for the celery extract (CE) was determined to be 0.1% and it was formulated into a cream. A total of 30 female Sprague Dawley rats were divided into five groups: Group 1, negative control; Group 2, positive control; Group 3, treated with 0.05% CE cream; Group 4, 0.1% CE cream; and Group 5, 0.2% CE cream. All animals in the groups were exposed to a full-thickness skin biopsy on the dorsal portion, and they were infected with 30 µL of 10⁵ colony-forming units of the MRSA isolate. The treatment was administered twice a day for 7 days. The skin samples were collected on days 3 and 7 after the treatment. The skin tissue was examined histologically using hematoxylin and eosin, Gram staining, and immunohistochemistry against cytokeratin (CK)-17.

Results:

Results showed that 0.2% of CE cream was the best treatment for wounds infected with MRSA. CE (0.2%) cream increased skin reepithelialization, fibroblast proliferation, and CK-17 expression; it also decreased the percentage of wound area, inflammatory cell infiltration, and bacterial colonization in skin wound tissue compared to the other treatments (p≤0.05).

Conclusion:

This study demonstrated that celery could be utilized as an alternative herbal therapy against MRSA-associated skin infections.